Glomerular filtration rate (GFR) is a measure of how well your kidneys are filtering
blood:
1) What it measures
GFR estimates how much blood passes through the glomeruli, the tiny filters in your
kidneys, each minute.
2) How it's measured
A blood test measures the level of creatinine in your blood, a waste product that builds
up when your kidneys aren't working well. A mathematical formula is then used to
calculate your eGFR (estimated GFR) based on your creatinine level and other factors,
such as your age, weight, height, and sex.
3) What it indicates
A normal eGFR is 90 or higher. A lower eGFR may indicate kidney disease, with more
severe stages of kidney disease indicated by lower eGFRs:
4) eGFR 60–89: May indicate early-stage kidney disease
5) eGFR 15–59: May indicate kidney disease
6) eGFR below 15: May indicate kidney failure
7) Other factors that can affect GFR
Factors that can affect your GFR include your diet, muscle mass, and certain long-term
conditions.
GFR is considered the best way to measure kidney function. It can help detect kidney
disease, understand its severity, and make decisions about diagnosis, prognosis, and
treatment.